Google AdSense may never make it onto the list of Facebook approved advertisers, resulting in a permanent ad revenue loss of 40 percent to 45 percent for developers.

Google AdSense — and possibly DoubleClick — may never make it onto the list of Facebook approved advertisers, resulting in a permanent ad revenue loss of 40 percent to 45 percent for developers.

So concludes a reader who’d forwarded the following email to us — and cc’ed two other blogs — from Google AdSense; the reader had asked when the service would comply with Facebook’s new advertising terms, which had a deadline of February 28.

Thanks for contacting us. I wish I could tell you otherwise, but I don’t think AdSense is on the list, and I’m not sure what the plans are going forward. I wouldn’t count on AdSense joining the list anytime soon, although I honestly have no information about this. Sorry for the bad news!

The same reader sent follow-up email to Google AdSense asking the same question, and received the following response came back:

Thank you for your email. We cannot comment on Facebook’s policies, or how they may change in the future. If you would like, feel free to contact Facebook and let them know you would like to be able to use AdSense in your Facebook Apps.

Right now, 77 advertising providers appear on Facebook’s approved list, meaning these vendors have all signed a statement agreeing to comply with the site’s policy about not sharing user data — among other rules posted here.

Facebook spokespeople’s communications with us thus far show that the social network hopes that AdSense might eventually comply with the ad provider rules, sign the statement and make it onto the approved list. That combined with the response our reader received suggests that Google might be the party digging its proverbial feet into the ground.

Readers, do you think Google AdSense will ever make it onto the list of approved advertising service providers?